I've see a few comments over the past month or so stating that running too high a fuel pressure will shorten the fuelpumps life. My question is why?

The way I see it, the pump outputs at max pressure (say 60psi) and regadless of what the AFPR is set at, the fuel not used is returned to the tank.

So why do some of you say that running excess fuel pressure will shorten the pumps life?

Comments?

 

Therein lies the flaw in your logic. The pump does not output max pressure. Our fuel pumps are a positive displacement design, which means they are always moving max volume. Pressure comes by way of the restriction of the FPR. At higher fuel pressure the pump has to push harder to move the fuel. Work harder = shorter life for an electric motor as it has to use more energy to work, and more energy means more current=more heat=death.
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